When classified, all living things have

What is the mass of an element with 15 protons, 13 electrons, and 11 neutrons? *

RSB [31]

Answer:

The mass of the element is 26.20 amu

Explanation:

In this question, we are asked to calculate the mass of an element with 15 protons, 13 electrons and 11 neutrons

To calculate the atomic mass of the element, we take into consideration the masses of the individual sub atomic particles

Electrons have 0 atomic mass unit(their masses are negligible) we have no business here, Protons have a mass of

1.00727647 amu, while the mass of neutron is 1.0086654 amu

The mass of 15 protons is thus 15 * 1.00727647 = 15.10914705 amu

The mass of 11 neutrons is 11 * 1.0086654 =

11.0953194 amu

Adding this together, we have ; 11.0953194 + 15.10914705 = approximately 26.20 amu

6 0

3 years ago

One of the reactions that occurs in a blast furnace, in which iron ore is converted to cast iron, is Fe2O3 + 3CO → 2Fe + 3CO2 Su

Tpy6a [65]

Answer : The percent purity of $Fe_2O_3$ in the original sample is 87.94 %

Explanation :

The given balanced chemical reaction is:

$Fe_2O3+3CO\rightarrow 2Fe+3CO_2$

First we have to calculate the mass of Fe.

$\text{Moles of }Fe=\frac{\text{Mass of }Fe}{\text{Molar mass of }Fe}$

Molar mass of Fe = 55.8 g/mole

$\text{Moles of }Fe=\frac{1.79\times 10^3kg}{55.8g/mole}=\frac{1.79\times 10^3\times 1000g}{55.8g/mole}=3.15\times 10^4mole$

Now we have to calculate the moles of $Fe_2O_3$

From the balanced chemical reaction we conclude that,

As, 2 moles of Fe produced from 1 mole of $Fe_2O_3$

So, $3.15\times 10^4mole$ of Fe produced from $\frac{3.15\times 10^4}{2}=15750$ mole of $Fe_2O_3$

Now we have to calculate the mass of $Fe_2O_3$

$\text{ Mass of }Fe_2O_3=\text{ Moles of }Fe_2O_3\times \text{ Molar mass of }Fe_2O_3$

Molar mass of $Fe_2O_3$ = 159.69 g/mole

$\text{ Mass of }Fe_2O_3=(15750moles)\times (159.69g/mole)=2.515\times 10^6g=2.515\times 10^3kg$

Now we have to calculate the percent purity of $Fe_2O_3$ in the original sample.

Mass of original sample = $2.86\times 10^3kg$

$\text{Percent purity}=\frac{\text{Mass of }Fe_2O_3}{\text{Mass of sample}}\times 100$

$\text{Percent purity}=\frac{2.515\times 10^3kg}{2.86\times 10^3kg}\times 100=87.94\%$

Therefore, the percent purity of $Fe_2O_3$ in the original sample is 87.94 %

3 0

3 years ago

Which is the stronger acid in each of the following pairs? Explain your reasoning.

Makovka662 [10]

Answer:p-hydroxybenzaldehyde is stronger acid to phenol

para-cyanophenol is stronger acid to meta-cyanophenol

o-fluorophenol is stronger acid to p-fluorophenol.

Explanation:

The PKa tool relative to Ph are used to contrast the pairs.

The pKa of phenol is 10. The pKa of p-hydroxybenzaldehyde is 9.24

The pKa for meta-cyanophenol is 8.61 and the pKa for para-cyanophenol is 7.95.

The pKa value of o-fluorophenol is 8.7, while that of the p-fluorophenol is 9.9. It's obvious that the inductive effect is more dominant at ortho-position, which results in a more acidic nature

The pKa is the pH value at which a chemical species will accept or donate a proton. The lower the pKa, the stronger the acid and the greater the ability to donate a proton in aqueous solution.

6 0

3 years ago

5 Which two elements are combined in magnesium oxide?

Vitek1552 [10]

Answer:

magnesium and oxygen

Explanation:

6 0

3 years ago

You dissolve 0.47 g of potassium chloride (KCl) in 700 ml of water.

lana [24]

Answer:

0.009

Explanation:

Molarity, a measure of molar concentration of a substance is calculated thus;

Molarity = number of moles ÷ volume

According to the provided information, mass of KCl = 0.47g, volume of water = 700ml

Using mole = mass/molar mass

Molar Mass of KCl = 39.10 + 35.453

= 74.553g/mol

Mole = 0.47/74.55

Mole = 0.0063mol

Volume of water = 700ml = 700/1000 = 0.7L

Molarity = 0.006/0.7

Molarity = 0.00857

The value of molarity rounded to three decimal places (3 d.p) = 0.009

6 0

3 years ago